Magneto



W. WALTHER July 29, 1930.

MAGNETO- Filed sept. 1, 1927y jfl Ver! fo r WMe/m l/VJ/f/7 ef .w Se

Patented .Iulv 29. 1930 uNiTEb sTATEs PATENT OFFICE WILHELM WALTHEB, F STUTTGART, GERMANY, ASSIGNOR T0 ROBERT BOBCE AKTIEN- GESELLSCHAFT, OF STUTTGART, GERMANY MAGNETO Application med september i, im, semi No.

The invention relates to magneto electric machines for the ignition arrangements of multi-cylinder engines.

It is known to make both the magnet and 5 the armature carrying the induction coil stationary and to conduct the lines of force from the magnet pole shoes to the armature through a rotating body.

An object of this invention is to consideri0 ably simplify and cheapen the manufacture.

For this purpose an annular or circular permanent magnet is arranged coaxially ad]acent the flux distributer so that the pole shoes are parallel to the axis of rotation. The inner curved faces of the pole shoes enclosing the flux distributer and the curved faces for the connection with the permanent magnet thus lie behind one another and concentrically of the 'axis of rotation. It is 2 consequently possible to' machine both these faces in a single operation by turning. In the construction hitherto usual two operations were necessary for this purpose and when usin horseshoe permanent magnets, the faces or the connection with the ole shoes had to be made by an expensive mil ing process.

One form of construction according to the invention is described by way of example 3 with reference to the accompanying drawin? in which igure 1 is a vertical longitudinal section of a magneto.

Figure 2 is a cross'section along the line w-Fg/ in Figure 1 and p igure 3 shows a detail on a larger scale. The permanent magnet a consists of a plurality of flat bar magnets, which, as shown in Figure 3, are of circular sha e with two ents cut away. A central liole is proed to allow passage of the steel shaft b of the flux'` distributer q, The flux distributer q is carried by the shaft b through the medium of a supportin hub c of nonmagnetic material fixed-to t e shaft in any suitable manner, as by a driving fit, The bundle of magnets a is secured against axial displacement y being pressed a ipgt shoulders d on the pole shoes e by a p te f mounted in the magneto housing by means of mapas, and in Germany sepeeinber as, im.

screws. The late f lias projections at both ends which grip the magnets laterally and so prevent rotation of the same about their. axis which coincides with the axis of rotation of the flux distributer g.

`As can be seen from Figure 1 the bundle of ma ets is located co-axially alongside the flux istributer g. This requires the pole shoes e to be dis osed parallel to the/shaft b. The inner curve faces g ,of the pole shoes facing the flux distributer, and the curved faces h or connecting the ole shoes with the ma nets a are consequent y located concentrical y of the axis which is common to the flux distributer and the bundle of permanent magnets. Thus the pole shoe faces g and h can durin manufacture be simultaneously machine in one operation by turning.

The winding i of the magnets is mounted on a fixed armature core k to which are attached armature shoes'm. The inner curved faces n of these shoes extend over the Iperipheri of the flux distributer g, toget er with t e inner faces of the pole shoes e. They may also bemac ined in common with the faces g and h. The winding z' consists as usual of low tension and hi h tension windings, which may be electrical y connected with the contact breaker o and the distributer p in known manner.

The armature core la, pole shoes e and m, and flux distributer q on the non-magnetic hub c, are made of sheet iron lamin. The

ole. shoes e and m are mounted in the housiiges by casting the latter around the pole s The magnetic circuit may be traced as follows: upper end of permanent magnet a, up@ per pole shoe e, uppermost segment of distributer q, pole shoe m nearest to -uppermod 0o segment of g, armature core k, other pole shoe m nearest to lowermost se ent of distributei q, lowermost se ent of 'stributer g, lower pole shoe e bac to loweiend of permanent ma et a.

claim: c

1. A magneto comprising in combination a stationary armature having windi and opposed arcuate pole pieces, a stationary permanent magnet, a rotary magnetic flux i distributer situated between said armature armature pole-pieces co-axial therewith and pole pieces coaxial therewith, and pole shoes for conductin the flux from said permanent magnet to said distributor, said pole shoes abutting the said magnet, and extending parallel with the axis of rotation of the linx distributer and havinv their pole faces and also the abutment surfaces between them and the magnet arrangement curved and concentric to said axis of rotation.

2. A magneto comprising in combination a stationary armature having windings and opposed arcuate pole pieces, a stationary disc shaped, permanent magnet, a rotary magnetic flux distributer situated between said armature pole pieces coaxial therewith, and pole shoes for conducting the iux from said permanent magnet to said distributor, said I pole shoes abutting the said magnet, and eX- tending parallel with the axis of rotation of the flux distributer and having their pole faces and also the abutment surfaces between them and the permanent magnet curved and concentric to said exis of rotation.

3. A magneto comprising in combination a stationary armature haring -windings and opposed arcuate pole pieces, a stationary magnet having arcuate polar surfaces, a rotary ma netic flux distributer situated between sai armature pole pieces coaxial therewith, and pole shoes for conducting the flux from said permanent magnet to said distributer, said pole shoes abutting the said magnet at said polar surfaces and extendingparallel with the axis of rotation of the flux distributer and havin their pole faces and also the abutment sur aces between them and the polar surfaces of the stationary magnet concentric to said axis of rotation.

4. A magneto com rising in combination n. stationary armature aving windings and opposed arcuate pole pieces, a stationar permanent magnet, a rotary magnetic ux distributar situated between said armature pole pieces coaxial therewith, and pole shoes for conducting the ilux from said permanent magnet to said distributer having pairs of machined faces co-axial and lying respectively opposite the flux distributer and enclosing t e magnet.

5. A magneto comprising in combination a i stationary armature aving windings and opposed, arcuate pole-pieces, a permanent magnet having arcuate polar faces, a rotary ma netic lux distributor situated between said armature pole-pieces co-axial therewith, and

pole shoes having pairs vof arcuate faces coaxial and lying respectively opposite the periphery of the flux distributer and in contact with the arcuate polar faces of the permanent magnet.

6. A'magneto comprising in combination, a stationary armature aving windings and opposed, arcuate pole-pie'ces, a permanent magnet, a ux dstributer situated between said pole shoes extending from said ma net to the distributer for conducting the ux from said permanent magnet to said distributer, said pole shoes and magnet being arranged in fixed contact through arcuate surfaces.

In testimony whereof I have hereunto affixed my signature.

WILHELM WALTHER. 

